I played the previous two Gundam Battle games on PSP and they were both enjoyable B- quality games, but it looks like Battle Chronicles is going to amp things up a bit, according to what I've just read:
Game Star has details about the PSP game, coming October 4. It's listed as the 3rd in the Gundam Battle series, following the previous Gundam Battle Tactics and Gundam Battle Royale. The game has complete campaign missions for First, Z, and 0083 and also at least includes MS from ZZ and CCA. With the new chain mission system, mission content changes constantly based on gameplay circumstances. Coop play is possible on all the over 100 missions so if one person is having trouble clearing a particular one, they can bring in a friend to help. Versus mode formats (1 vs. 1, 1 vs. 3, etc.) can be freely chosen. Additional missions and other elements will be unlockable via passwords given out through magazines. Every MS, as well as their weapons and shields, will be customizable using points you receive by clearing missions.
The latest issue of Famitsu reveals the game includes space and underwater missions as well as the following mobile suits: S Gundam, GP02, Dendrobium, Xamel, Gerbera Tetra, GP01, Nu Gundam, ZZ Gundam, Qubeley, Psyco Gundam Mk II, Dijeh, The O, Gabthley, and Baund Doc.
Edit: Happinet Online says there'll be over 140 MS and 120 missions.
I'm sure probably 20 or so of those MS's are just color variants, but that's still quite a bit of units for the game.
The games play a bit like the arcade games designed by Capcom, but with more strategic type missions and more units on either side.